Effect of pore size distribution on sorption-induced deformation of porous materials: A theoretical study
Effect of pore size distribution on sorption-induced deformation of porous materials: A theoretical study
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DOI：
10.1016/j.ijsolstr.2022.111533
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发表时间：
2022-03-03
影响因子：
3.6
通讯作者：
Zhang, Yida
中科院分区：
文献类型：
--
作者：
Eskandari-Ghadi, Mehdi;Zhang, Yida
多孔材料在与环境中的吸附物相互作用时表现出复杂的变形。根据单个孔的大小和形状，固体和吸附物之间的相互作用可以产生影响整体吸附和应变等温线的几个孔尺度力。多孔材料的吸附变形行为的准确预测将受益于考虑其由孔径分布（PSD）描述的孔网络特性。本文提出了一种理论研究的孔径分布可以影响吸附诱导变形的微/介/大孔固体。将新近发展的表面孔隙力学理论推广到任意孔径分布的信息。一个通用的孔隙网络的吸附能量统计放大从固体吸附物的相互作用，在一个单一的狭缝孔的几何形状，然后注入到一个可变形的身体的热力学。该理论首先验证了对微孔碳与氮气相互作用的实验数据。然后，使用相同的参数集来研究孔径对多孔材料的吸附和应变等温线的影响。通过只改变输入PSD，各种吸附变形行为，通常从实验观察到的模型再现。从这个分析得出结论，在不同的孔径范围内，不同的孔隙尺度的力量的相对优势，和简化的孔隙网络的表示可以接受的情况。
Porous materials exhibit complex deformation when interacting with adsorbates in the environment. Depending on the size and shape of individual pores, interactions between solid and adsorbates can give rise to several pore scale forces that impact the overall adsorption and strain isotherms. Accurate prediction of the adsorption deformation behavior of a porous material would benefit from the consideration of its pore network characteristics described by the pore size distribution (PSD). This paper presents a theoretical investigation on how the pore size distribution can affect the sorption-induced deformation of micro/meso/macro porous solids. The recently developed surface poromechanics theory is generalized to account for the information of arbitrary pore size distributions. The adsorptive energetics of a generic pore network is statistically upscaled from the solid adsorbate interaction in a single slit pore geometry, which is then infused into the thermodynamics of a deformable body. The theory is first validated against the experimental data on microporous carbon interacting with nitrogen gas. Then the same parameter set is used to study the effects of pore size on the adsorption and strain isotherms of porous materials. By only varying the input PSDs, a variety of adsorption-deformation behaviors that are commonly observed from experiments is reproduced by the model. Conclusions are drawn from this analysis regarding the relative dominance of different pore-scale forces at varying pore size ranges, and the circumstances where simplified representation of the pore network can be acceptable.